Ergo, GSM (2G) dates back to the late 1980's, and an old air interface like this was developed when not every 9 year old had cellphones and yakked on them for hours on end. We also didn't have masses of electronics around the house. One must also take into consideration that older consumer electronics built "back then" was usually over engineered compared to todays stamped out everything on a chip in an el cheapo plastic case design.

FYI CDMA transceivers (such as those used by Verizon, Sprint PCS, Alltel, US Cellular, Cricket and Metro PCS to name a few) don't cause RFI to devices because their transmitters don't pulse rapidly and they are spread spectrum in nature so their RF output is spread across 1.5MHz (CDMA2000) channels. CDMA was chosen for the 3G GSM standard as an air interface, so theoretically a Cingular 3GSM phone operating in a 3GSM areas shouldn't wreck your precious speakers.

Or you could just follow the manufacturer's instructions and not place radio transmitting equipment near your audio amplifiers, TV's or speakers.

Cellphones are just two-way radios...do remember to turn them OFF in hospitals, near blasting caps, or when near a terrorist bomb or explosive device.

MrFlashport

mainfr4me

From: Cingular Wireless Email Customer Service [mailto:XXXXXXX@cingular.com]
Sent: Monday, April XXXXXXXXXX
To: XXXXXXXXXXXXX
Subject: Re: Cingular Wireless Customer Email - XXXXXX - [TECH]
(XXXXXXXXXXXXXX)

Dear Mr. XXXXXXXXX,

Thank you for contacting Cingular Wireless with your questions regarding
the replacement of your handset due to the interference received on your
car radio when the service is used. I do apologize for the
inconvenience this issue has caused you and I will be happy to assist
you today.

The signal for wireless phones is, in essence, a radio signal and can be
affected by the same structures and interference that would block a
radio station signal. Please know that network signal strength can
depend on a variety of factors, including weather, terrain, building
structure interference, call demand and your device and when the service
on the handset is used near a radio which is being played, the
interference that you are hearing will most likely occur. This can also
happen when using the handset near a microwave. Because of the many
factors that can affect cell phone signal strength, we are not able to
guarantee 100% coverage and we would not be able to allow an early
upgrade due to this issue.

As your handset will not be eligible for the equipment upgrade process
until 09/16/05, if you wish to make the purchase of a new handset at
this time you would need to do so at full retail cost. As this type of
purchase cannot be made through your online account due to the pricing,
you would need to either visit your local retail store, or call Customer
Service at 1-800-331-0500 for assistance. The representative that you
speak with would be able to advise you of the current retail pricing at
the time of your inquiry. Since the equipment pricing is subject to
change at any time, we are not permitted to quote the pricing via email.
Again Mr. XXXXXXX, I do apologize for the inconvenience and frustration
this issue has caused you.

We encourage you to visit our web site, www.cingular.com, often to view
current and previous monthly statements, make payments and to shop for
new product and service offerings. If you have any further questions or
concerns please do not hesitate to contact us. We do appreciate the
fact that you have been a valued customer with us since 12/16/05! Again
Mr. XXXXXXXXX, thank you for contacting Cingular!

Sincerely,

XXXXXXXXXXXXX
Cingular is now the new AT&T
Online Customer Care Professional

Red_Eye

- Radio Shack Pro-95 police scanner
- Sony alarm clock radio
- Conference room speakerphone
- B&W CM2 stereo speakers

When driving around, I can tell whenever my phone switches cell towers as it tkktktktttt's through the Pro-95. I have to use strategery when placing my phone anywhere close to the alarm clock on my nightstand, or else it will wake me up when sqwaking with the network. My co-workers constantly give me the stink-eye in meetings and love to say "Is that your phone?" when the conference call speakerphone starts alerting all to an incoming call. And, now, I can't get too close to my home stereo for fear of having a Justin-esque asplosion on my sweet, sweet B&W's.

And my old AT&T TDMA Nokia 6560 never made a peep.

chopchopturtleboy

secret

My phone automatically switches providers if my T-Mo reception is weak (esp in rural areas).

superbmtsub

Almost all audio amplifiers are controlled at the low-level stage, and if RF happens to enter the circuit after the volume control, again, it might very well drive the amplifier to full output and damaging the speakers. It could also cause the amplifier to oscillate, thus damaging the amplifier. Anything that radiates RF energy has the potential to do this.

From the Wikipedia entry on "GSM."

A nearby GSM handset is usually the source of the "dit dit dit, dit dit dit, dit dit dit" signal that can be heard from time to time on home stereo systems, televisions, computers, and personal music devices. When these audio devices are in the near field of the GSM handset, the radio signal is strong enough that the solid state amplifiers in the audio chain function as a detector. The clicking noise itself represents the power bursts that carry the TDMA signal. These signals have been known to interfere with other electronic devices, such as car stereos and portable audio players. This is a form of RFI, and could be mitigated or eliminated by use of additional shielding and/or bypass capacitors in these audio devices, however, the increased cost of doing so is difficult for a designer to justify.

That's pretty much it in a nutshell. Your phone is a miniature transmitter and it puts out RF energy which can get into other devices. GSM uses a single frequency with multiple time slots, while CDMA uses spread spectrum which is less likely to interfere with consumer devices. Consumer electronics manufacturers skimp on the shielding for stereos, computers, and TV's because it costs them extra to build into their product.

☠Gяяяяяяя! I want to sing the doom song now!

Sachin Agarwal

I use T-Mobile btw. Moto V-360, the fat, microsd verion of the Razr.

cde

Buran

T Mobile models do this too. It's just a fact of life with GSM. I play in a band and three of us have RAZRs with different GSM providers and if we don't turn them off you hear it through the guitar amps, the PA amps, and the monitors.

Now I am not sure how he damaged it... I have had a 600W power amp running into an Ampeg SVT8x10 with the "click-beep-buzz" sounds (I too use Cingular, BTW), but the speakers work fine. Doesn't sound half as bad as when someone turns off the preamp before the power amp.

jurgis

If the equipment is properly shielded, then nothing happens...

So basically, i had to retransfere all the tapes with the phone turned off and the battery removed.

shdwsclan

ElizabethD

Macroy

Clever bit with the apple logo being one of the eyes of the cingular logo.

valkin

LAGirl

fhic

Mobius

shad0ws

Easiest is keep your cellphone away from your computer and stereo.

cde

BareFeet

It's the same inductance that is used to make those led flashers that go off when you get a call, like this one: CELL-PHONE-BUDDY-LED-FLASHING-LIGHT-FL...ASHLIGHT_W0QQitemZ320106365908QQihZ011QQcategoryZ3311QQrdZ1QQcmdZViewItem">http://cgi.ebay.com/CELL-PHONE-BUDDY-LED-FLASHING-LIGHT-FL......

And I for one use this on my phone to get a call. I place it right by my speaker cable so that even if its on vibrate because I forgot to switch it after work or class, I can still hear it.

Oh, and as a side note, cellphone companies should be held liable for the phones they sell. Manufactures cater to them in design specs and custom (and mostly user disabling) firmwares, and they use them to make a profit. If you're going to slap your name on something and prevent people from using it on other services, you should be as liable as the manufacturer. Even more so since the customer deals with you directly and only has a third party relationship with the manufacturer.

cde

Faulting the phone for generating EM radiation is like faulting a microwave for generating microwaves. That's what it does. The amp/speakers need to properly shielded to avoid this coupling. Operating the amplifier unshielded with a high enough gain to damage the speakers is Justin's mistake, not Cingular's.

wikkit

kadtech

Living near an airfield, speakers will sometimes be actuated with radio traffic. Here at the office, there's a phantom signal that'll come through once or twice a month, still haven't tracked it down to exactly what it is, as it'll hit multiple speakers, but only for a split second. The glory that is radio.

KF4

They must have been turned up way too loud as well, i have a pair of speakers that does this as well, but it has never caused any problems.

boxoman

That means "Your license to use this device does not permit you to cause harmful interference", not "This device is incapable of causing harmful interference".

That's why it's a condition of operation. (You are the operator of the device.)

mendel

(my old motorola i530 does this. people think its strange when i answer my phone before it ever rings. . .)

3ZKL

Monty

Sathallrin

To stop this,you would have to use a time division that divided signals faster then the speakers response, which would be >30kHz, or stop using time divided signals all together. There are difficulties in implementing both of these ideas.

This interaction is not present on Sprint/Verizon phones because they use CDMA, or code based division, which means every phone sends at the same time as every other phone, and fancy math figures out who sent what. (GSM also uses frequency division to separate towers.. so one tower will be 1830.5 Mhz, and another will be 1828 Mhz).

Wikipedia has some great articles on CDMA, GSM, TDMA, and FDMA if you're interested in learning more.

miradu

Buran

Red_Eye

Buran

Red_Eye

Ben Popken

But my Verizon (Motorola) phones have never done this. It might be the frequency they use. But true, very very annoying.

I would have the phone on silent when I went to bed, and my computer speakers would alwasy be on and they would start making that noise. They should probably work on fixing that.

By the way, yes its not cingular that makes the phones. But they do support them and put their logo. So you should therefore be providing good equipment...

Coder4Life

The signal output power and frequency is likely the same as any other GSM phone, correct? Perhaps the manufacturer of the phone used a higher-power transmitter? The GSM specifications likely have an acceptable range of transmitter power output. If the manufacturer designed the phone outside of any specified parameters then I can see some blame directed at them.

Eric

castlecraver

Gari N. Corp

@DarienA:

It's not really RF leakage. Cell phones are radio transceivers; if you build one that doesn't 'leak' RF, it won't be very useful. This is more the fault of the speaker/amplifier manufacturers (who don't seem to have provided adequate shielding for the audio signal lines) than anyone else.

Speaker damage can be caused by high-power signals with sharp-edged waveforms (square waves, clipped sine waves, and so forth - the extremely sharp voltage transients fight the inertia of the speaker cone, causing it to tear.) My guess is that Justin's phone induced a fairly loud signal at the input of the speaker amp, which was then badly clipped and fed to the speakers. This sucks, but it's far from unheard of - and he may have no recourse since the speakers are Part 15.

velocipenguin

TexasScout

It would also happen at other people's houses... and at K-mart when I was walking through the stereo section.

It quit when I upgraded to a Samsung slider phone.

kimdog

The worst RF leakage I've ever seen in a phone.

DarienA

CaptainRoin

cingular doesn't build phones!

chimmike

[forum with an overview]

http://www.blackberryforums.com/hardware-accessories/7813-...

Sorry to hear this fellow had his phone near an unshielded amplifier input; I've gotten pretty loud feedback over some of my less expensive wiring to unamplified speakers when i have mine sitting parallel and on top of them.

:(

Takashi-Monobito

faust1200

I spent hours troubleshooting my speakers - I first thought it was my computer, so I unhooked em.
They still made the sound every once in a while, so I thought they were bad - no biggie, bought another set.
Same damn noise!
Okay, maybe there is something odd with the 120v in this house - bought a circuit isolator.
STILL THE DAMN CLICKCLICKclickclickCLICK noise!

Finally figured out it was the damn phone in my pocket. Grr.

zsouthboy

BareFeet

joeblevins

Also, it's the guy's AMPLIFIER that makes the signal stronger, not the phone. He must have had it turned up pretty loud and the phone very clmTIM/VAP

xkaluv

"This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that may cause undesired operation."

So if he can prove that his phone put out the interference, then he may be able to get restitution. This also lets the speaker manufacturer off the hook.

Pasketti

Yet my T-Mobile phone sits right by my speakers but it doesn't affect them.

davere